Conventionally, it is known that a cylindrically shaped printing plate is configured to be attached to an outer circumferential surface of a cylindrical plate cylinder fixedly provided on a plate drive shaft from the front end of the plate drive shaft.
The plate cylinder described in Patent Document 1 is provided with a circumferential direction positioning groove to which an engaging part of a plate is fitted from the front end side and an axial direction positioning stopper arranged at the rear end of the plate cylinder and configured to be brought into contact with the end portion of the printing plate.